1. Department of Physics, St. Teresa's College, Ernakulam, Kerala 682011, India
2. International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam, Kerala 686560, India
3. School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala 686560, India
4. International Centre for Ultrafast Studies, Mahatma Gandhi University, Kottayam, Kerala 686560, India